oo_example.pl

#---------------------------------------------------------------------------
#  Foo
#---------------------------------------------------------------------------

package Foo;
use Moose;

has 'name' => ( is => 'rw', isa => 'Str' );

sub hello {
    my $self = shift;
    print $self->name, "\n";
}

#---------------------------------------------------------------------------
#  Bar
#---------------------------------------------------------------------------

package Bar;

sub new {
    my ($class, %args) = @_;
    my $self = bless \%args, $class;
    return $self;
}

sub name {
    my ($self, $new_value) = @_;
    $self->{name} = $new_value if $new_value;
    return $self->{name};
}

sub hello {
    my $self = shift;
    print $self->name, "\n";
}

1;

#---------------------------------------------------------------------------
#  main
#---------------------------------------------------------------------------

package main;

my $foo = Foo->new(name => 'FOO');
$foo->hello;

my $bar = Bar->new(name => 'BAR');
$bar->hello;